FOSTER CITY, Calif. & INGELHEIM, Germany--(BUSINESS
WIRE)--Oct 5, 2011 - Gilead Sciences, Inc. (Nasdaq:GILD) and
Boehringer Ingelheim today announced that the companies have
entered into a licensing agreement, under which Boehringer
Ingelheim has granted Gilead exclusive worldwide rights for the
research, development and commercialization of its novel
non-catalytic site integrase inhibitors (NCINIs) for HIV. This
includes the lead compound BI 224436, which has been evaluated in a
Phase 1a dose-escalation study to assess bioavailability and
pharmacokinetics in healthy volunteers.

NCINIs target the key component of the HIV virus responsible for
incorporation of the viral DNA into the human genome. NCINIs
inhibit HIV integrase by binding to a novel site, distinct from the
catalytic site used by the current class of integrase inhibitors,
and therefore may possess a differentiated resistance profile from
raltegravir or elvitegravir.

“We are very pleased to have established this licensing
agreement. The Boehringer Ingelheim compounds complement our
internal discovery programs and the efforts are aligned with our
commitment to continue to innovate in the field of HIV,” said
Norbert Bischofberger, PhD, Executive Vice President, Research and
Development and Chief Scientific Officer, Gilead Sciences.
“We are looking forward to progressing BI 224436 or other
compounds further into clinical development.”

“Both companies' genuine interest in advancing research
and development in virology is reflected by this collaboration's
aim to address unmet patient needs,” said Prof. Dr. Klaus
Dugi, Corporate Senior Vice President Medicine at Boehringer
Ingelheim. “While Gilead will drive the integrase inhibitors
in HIV into clinical development, we will focus our development
efforts on further compounds of our virology pipeline, particularly
our portfolio in hepatitis C.”

Under the terms of the agreement, Gilead will pay Boehringer
Ingelheim an upfront payment. Boehringer Ingelheim could receive
additional payments based upon the achievement of certain
development, regulatory and commercial milestones, as well as
royalties on future net sales.

About Gilead Sciences

Gilead Sciences is a biopharmaceutical company that discovers,
develops and commercializes innovative therapeutics in areas of
unmet medical need. The company's mission is to advance the care of
patients suffering from life-threatening diseases worldwide.
Headquartered in Foster City, California, Gilead has operations in
North America, Europe and Asia Pacific. For more information on
Gilead, please visit www.gilead.com.

About Boehringer
Ingelheim

The Boehringer Ingelheim group is one of the world's 20 leading
pharmaceutical companies. Headquartered in Ingelheim, Germany, it
operates globally with 145 affiliates and more than 42,000
employees. Since it was founded in 1885, the family-owned company
has been committed to researching, developing, manufacturing and
marketing novel products of high therapeutic value for human and
veterinary medicine.

As a central element of its culture, Boehringer Ingelheim
pledges to be socially responsible including involvement in social
projects, caring for employees and their families, and providing
equal opportunities for all employees form the foundation of the
global operations. Mutual cooperation and respect, as well as
environmental protection and sustainability are intrinsic factors
in all of Boehringer Ingelheim's endeavors.

In 2010, Boehringer Ingelheim posted net sales of about 12.6
billion euro while spending almost 24% of net sales in its largest
business segment, Prescription Medicines on research and
development.

This press release includes forward-looking statements, within
the meaning of the Private Securities Litigation Reform Act of
1995, that are subject to risks, uncertainties and other factors
that could cause actual results to differ materially from those
referred to in the forward-looking statements, including the
risk related to the development of Boehringer Ingelheim's
novel NCINIs for HIV, including BI 224436. There are also risks
related to current and future clinical studies of BI 224436,
including the possibility of unfavorable results and the need to
modify or delay the studies or to perform additional trials. As a
result, Boehringer Ingelheim's novel NCINIs for HIV, including BI
224436, may never be successfully commercialized. In addition,
Gilead may make a strategic decision to discontinue development of
Boehringer Ingelheim's novel NCINIs for HIV, including BI 224436.
These and other risks are described in detail in Gilead's Quarterly
Report on Form 10-Q for the quarter ended June 30, 2011, as filed
with the U.S. Securities and Exchange Commission. All
forward-looking statements are based on information currently
available to Gilead, and Gilead assumes no obligation to update any
such forward-looking statements.